Antibodies directed against the pancreatic islet cell plasma membrane detection and specificity

Research output: Contribution to journalArticle

Abstract

Rabbits were immunised with suspensions of viable, insulin-producing islet cells prepared from collagenase-isolated rat or ob/ob mouse pancreatic islets. Antibodies reactive with the surface of dispersed rat islet cells were present in both the rabbit anti-rat and the rabbit anti -ob/ob mouse islet sera as revealed by indirect immunofluorescence or by a radioligandassay using 125 I-Protein A as a measure of cell bound IgG. In a competition assay the binding of 125 I-Protein A was displaced in a concentration dependent manner by non-radioactive Protein A. Maximal displacement was found at concentrations of Protein A higher than 0.1 μg. added to 10 5 islet cells. Although not always detected by immunofluorescence there was a several-fold increase above normal rabbit serum of 125 I-Protein A-binding to rat hepatocytes and spleen lymphocytes incubated with the islet cell antisera. Conversely, rabbit antisera against rat spleen lymphocytes or against a rat liver plasma membrane preparation reacted with rat islet cells. The rabbit anti-rat islet cell antiserum was absorbed to both spleen lymphocytes and hepatocytes until there was no binding of 125 I-Protein A to either cell type. Islet specific antibodies were still present since this doubly absorbed antiserum induced cell surface immunofluorescence as well as 125 I-Protein A-binding to rat islet cells. It is concluded that apart from common antigenic determinants immunisation with viable islet cells induces formation of antibodies directed against specific islet cell surface components.

Details

Authors
  • Å Lernmark
  • T. Kanatsuna
  • C. Patzelt
  • K. Diakoumis
  • R. Carroll
  • A. H. Rubenstein
  • D. F. Steiner
External organisations
  • University of Chicago
  • Hagedorn Research Institute
Research areas and keywords

Keywords

  • autoimmunity, cell surface antigens, cell surface immunofluorescence, cell suspensions, diabetes mellitus, islet cell surface antibodies, Pancreatic islet cells, Protein A radioassay
Original languageEnglish
Pages (from-to)445-451
JournalDiabetologia
Volume19
Issue number5
Publication statusPublished - 1980 Nov 1
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes